Methods of making chlorinated hydrocarbons

ABSTRACT

Methods for the manufacture of 1,1,1,2,3-pentachloropropane from 1,1,1,3-tetrachloropropane and chlorine are disclosed. Improved methods are provided for the manufacture of 1,1,2,3-tetrachloropropene from 1,1,1,2,3-pentachloropropane. Methods are also disclosed for the manufacture of 1,1,2,3-tetrachloropropene from 1,1,1,3-tetrachloropropane and chlorine and for the manufacture of 1,1,2,3-tetrachloropropene from carbon tetrachloride, ethylene, and chlorine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Non-Provisionalapplication Ser. No. 14/554,883, filed on Nov. 26, 2014, which is acontinuation application of U.S. Non-Provisional application Ser. No.14/081,377, filed on Nov. 15, 2013, which is a continuation applicationof U.S. Non-Provisional application Ser. No. 13/588,240, filed Aug. 17,2012, which is a divisional application of U.S. Non-Provisionalapplication Ser. No. 13/272,561, filed Oct. 13, 2011, which is adivisional application of U.S. Non-Provisional application Ser. No.12/337,409, filed Dec. 17, 2008, which claims the benefit of U.S.Provisional Application No. 61/014,981, filed Dec. 19, 2007, the entiredisclosure of each is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates to methods of manufacturing chloropropenes andchloropropanes, and more particularly to the manufacture of1,1,2,3-tetrachloropropene and 1,1,1,2,3-pentachloropropane.

BACKGROUND

Chlorinated hydrocarbons are useful as feedstocks for the manufacture ofrefrigerants, polyurethane blowing agents, biocides, and polymers.1,1,2,3-Tetrachloropropene, for example, is a commercially availableproduct used as a feedstock for the herbicide Triallate(S-(2,3,3-trichloro-2-propenyl) bis(1-methylethyl)carbamothioate).1,1,1,2,3-Pentachloropropane can be used as an intermediate for themanufacture of 1,1,2,3-tetrachloropropene. Methods for manufacturing1,1,2,3-tetrachloropropene are described in the art, including in U.S.Pat. No. 4,535,194 and U.S. Pat. No. 4,650,914.

SUMMARY

The present application describes novel methods of making chlorinatedhydrocarbons such as 1,1,2,3-tetrachloropropene and1,1,1,2,3-pentachloropropane. These chlorinated hydrocarbons can beused, for example, as feedstocks to produce fluorocarbons. The1,1,1,2,3-pentachloropropane may be used as an intermediate to produce1,1,2,3-tetrachloropropene. The methods can provide for improvedefficiency and provide for synergy in combinations of chemicalreactions.

In one embodiment, the systems and methods disclosed herein include aprocess of making 1,1,1,2,3-pentachloropropane, the process comprisingheating 1,1,1,3-tetrachloropropane in the presence of ferric chlorideand chlorine to produce 1,1,1,2,3-pentachloropropane.

In another embodiment, the systems and methods disclosed herein includethe manufacture of 1,1,2,3-tetrachloropropene, includingdehydrochlorinating 1,1,1,2,3-pentachloropropane in a reaction zone inthe presence of ferric chloride to produce 1,1,2,3-tetrachloropropeneand hydrogen chloride, wherein the 1,1,2,3-tetrachloropropene and thehydrogen chloride are substantially continuously removed from thereaction zone as they form, via distillation.

In another embodiment, the systems and methods disclosed herein includea process for the manufacture of 1,1,2,3-tetrachloropropene, including(i) reacting 1,1,1,3-tetrachloropropane with chlorine in the presence offerric chloride to produce crude 1,1,1,2,3-pentachloropropane; (ii)feeding crude 1,1,1,2,3-pentachloropropane into a reaction zone, totransform the crude 1,1,1,2,3-pentachloropropane into1,1,2,3-tetrachloropropene and hydrogen chloride by dehydrochlorination,wherein the 1,1,2,3-tetrachloropropene and hydrogen chloride are removedfrom the reaction zone during the course of the dehydrochlorinationreaction, the feeding and removal preferably being performedsubstantially continuously; and (iii) collecting1,1,2,3-tetrachloropropene.

In another embodiment, the systems and methods disclosed herein includethe manufacture of 1,1,2,3-tetrachloropropene, including (i) reactingcarbon tetrachloride with ethylene in the presence of iron chlorides,iron metal, and a trialkylphosphate in a first reaction zone to producereactor effluent containing 1,1,1,3-tetrachloropropane; (ii) distillingsaid reactor effluent to produce an overhead stream and a bottom stream,the overhead stream comprising a crude 1,1,1,3-tetrachloropropanesolution comprising unreacted carbon tetrachloride and zero or morelow-boiling contaminants, and the bottom stream comprising1,1,1,3-tetrachloropropane, iron metal, iron compounds, one or morephosphorus-containing catalyst components, and high-boiling byproducts;(iii) reacting in a second reaction zone the overhead stream withchlorine in the presence of ferric chloride to produce crude liquid1,1,1,2,3-pentachloropropane; (iv) feeding crude product from (iii) to athird reaction zone, which is part of a reactive distillation process,the reactive distillation process equipment comprising a reaction zone,a separation zone, and a condensing zone, to transform the crude1,1,1,2,3-pentachloropropane into hydrogen chloride and1,1,2,3-tetrachloropropene, wherein the hydrogen chloride and1,1,2,3-tetrachloropropene are continuously removed from the reactionzone, and (v) recovering purified 1,1,2,3-tetrachloropropene product.

In another embodiment, the systems and methods disclosed herein includethe manufacture of 1,1,2,3-tetrachloropropene, including: (i) reactingcarbon tetrachloride with ethylene in the presence of iron chlorides,iron metal, and trialkylphosphate to produce a reactor effluentcomprising 1,1,1,3-tetrachloropropane; (ii) distilling said reactoreffluent to produce an overhead stream and a bottom stream, the overheadstream comprising a first crude 1,1,1,3-tetrachloropropane solutioncontaining unreacted carbon tetrachloride and zero or more low-boilingcontaminants, and the bottom stream comprising1,1,1,3-tetrachloropropane, iron compounds, one or morephosphorus-containing catalyst components, and high-boiling byproducts;(iii) distilling the first crude 1,1,1,3-tetrachloropropane solutionfrom ii) to produce a substantially pure carbon tetrachloride stream,comprising more than 90 weight percent (wt %) carbon tetrachloride, anda second crude 1,1,1,3-tetrachloropropane solution comprising no morethan 10 wt % carbon tetrachloride; (iv) recycling a portion of thesubstantially pure carbon tetrachloride stream from (iii) to the reactor(i); (v) reacting the second crude 1,1,1,3-tetrachloropropane solutionfrom iii) with chlorine in the presence of ferric chloride underconditions effective to produce a reactor effluent containing1,1,1,2,3-pentachloropropane and ferric chloride; (vi) continuouslyfeeding reactor effluent from (v) to a reactive distillation process,the reactive distillation process equipment comprising a reaction zone,a separation zone, and a condensing zone, to transform the crude1,1,1,2,3-pentachloropropane into hydrogen chloride and1,1,2,3-tetrachloropropene, wherein the hydrogen chloride and1,1,2,3-tetrachloropropene are continuously removed from the reactionzone, and (vii) recovering 1,1,2,3-tetrachloropropene product.

One or more of the following features may be included in theembodiments:

the 1,1,1,3-tetrachloropropane, ferric chloride and chlorine may beheated in a liquid mixture with carbon tetrachloride;

the carbon tetrachloride may be present in an amount up to about 50 wt %of the reaction mixture, preferably in an amount from 3 to 30 wt % ofthe reaction mixture;

the ferric chloride may be present in a catalytic amount, such as in arange of from about 10 to about 1000 ppm, for example about 10 to about1000 ppm or about 30 to about 1000 ppm or about 50 ppm to about 1000ppm;

the reaction temperature may be from about 40° C. to about 120° C., andthe reaction pressure may be in the range from about 1-300 psig;

the process may be a continuous process, and the1,1,1,3-tetrachloropropane and chlorine may be continuously fed into areaction zone containing ferric chloride; the ferric chloride may becontinuously fed into a reaction zone, or periodically fed into areaction zone; the 1,1,1,3-tetrachloropropane and chlorine may beintroduced with a feed ratio of from about 0.9 to about 1.1 molechlorine per mole tetrachloropropane;

the ferric chloride may be fed into a reaction zone at least once per0.5 to 3 liquid turnovers (wherein one turnover is the time calculatedas the ratio of liquid inventory in the reactor to the liquid flow rateout of the reactor);

addition of reagents and removal of products may be performedcontinuously, substantially continuously, or batch-wise periodically.

One or more of the following additional features may also be included inthe embodiments:

at least a portion of the process may occur in equipment comprising areaction zone, a separation zone, and a condensing zone; the separationzone may include a distillation component;

hydrogen chloride may be a coproduct of the process and may be removedfrom the reaction zone through a separation zone and a condensing zone;the hydrogen chloride coproduct exiting the reaction zone containsimpurities, such as one or more of 1,1,3-trichloropropene or carbontetrachloride; the carbon tetrachloride and/or 1,1,3-trichloropropeneare recycled into the reaction zone via the condensing zone; theseparation zone comprises an empty tube or a tube containing packing orother structure suitable for promoting vapor-liquid contacting, and thecondensing zone comprises a vessel suitable for causing some of thecomponents of the hydrogen chloride stream, such as1,1,3-trichloropropene or carbon tetrachloride, to condense as a liquid;crude 1,1,1,2,3-pentachloropropane may be continuously removed from thereaction zone; 1,1,1,2,3-pentachloropropane may be dehydrochlorinated toproduce 1,1,2,3-tetrachloropropene, and the crude1,1,1,2,3-pentachloropropane reactor effluent may be dehydrochlorinateddirectly, without prior purification and without added catalysts orreagents; and the 1,1,2,3-tetrachloropropene product may besubstantially free of 2,3,3,3-tetrachloropropene.

In some embodiments, the methods provide for fewer processing steps thanwas disclosed in the art. In some embodiments, the methods avoid the useof certain reagents that were disclosed in the art methods. In someembodiments, the methods reduce the waste streams produced relative tothe art methods.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 shows a continuous process to produce1,1,1,2,3-pentachloropropane from a feedstock containing1,1,1,3-tetrachloropropane.

FIG. 2 shows a continuous process for the manufacture of1,1,2,3-tetrachloropropene from a feedstock containing1,1,1,2,3-pentachloropropane.

FIG. 3 shows a two-step continuous process to make1,1,2,3-tetrachloropropene from feedstocks containing1,1,1,3-tetrachloropropane and chlorine.

FIG. 4 shows a three-step continuous process to make1,1,2,3-tetrachloropropene from ethylene, carbon tetrachloride, andchlorine feedstocks.

FIG. 5 is a graph depicting the rate of formation of1,1,2,3-tetrachloropropene versus time, in connection with Examples 2-4.

FIG. 6 depicts the lab equipment used in an Exemplary continuous processto produce 1,1,1,2,3-pentachloropropane.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION 1. Processes for Producing1,1,1,3-Tetrachloropropane

In some embodiments, 1,1,1,3-tetrachloropropane is produced as describedin one of US20040225166A1, US2003000648709, or US20040027520, thecontents of each of which is hereby incorporated by reference.

US20040225166A1 describes a process for the synthesis of1,1,1,3-tetrachloropropane in which a fraction of the catalyst andcocatalyst are separated after the reaction and recycled wherein thereaction mixture is distilled in a catalyst recovery unit resulting inthe formation of “overhead fraction”. This overhead fraction contains1,1,1,3-tetrachloropropane and unreacted carbon tetrachloride, and someother components such as unreacted ethylene, or byproductsperchloroethylene, 1,2-dichloroethane, 1-chlorobutane, chloroform, ortrichloropropene. The overhead fraction as described in US20040225166A1can be further processed in methods and processes described herein, forexample, conversion of the 1,1,1,3-tetrachloropropane into1,1,1,2,3-pentachloropropane.

In some embodiments, the overhead fraction from the catalyst recoveryunit as described in US20040225166A1 can be separated to produce both astream containing an enhanced concentration of1,1,1,3-tetrachloropropane and a stream containing an enhancedconcentration of carbon tetrachloride. In this case, the recoveredcarbon tetrachloride and the relatively low-boiling byproducts containedtherein can be partially recycled to a 1,1,1,3-tetrachloropropanereaction, for example, a reaction described in US20040225166A1. A smallamount of the carbon tetrachloride can be purged from the system, forexample, as waste, or as a feedstock for other processes. The purging ofthe carbon tetrachloride can be effected to control the concentration oflow-boiling materials in the 1,1,1,3-tetrachloropropane reactor.

In some embodiments, the process producing 1,1,1,3-tetrachloropropanecan produce a product that contains up to about 50 wt % carbontetrachloride, for example, from about 3 to about 30 wt %, together withsmall amounts (e.g., less than about 5 wt % total) of materials such asperchloroethylene, 1,2-dichloroethane, 1-chlorobutane, chloroform, ortrichloropropene. In general, the 1,1,1,3-tetrachloropropane productdoes not contain more than trace quantities (e.g., less than 1000 ppmeach) of water or tributylphosphate or trialkylphosphate.

In some preferred embodiments 1,1,1,3-tetrachloropropane is produced bythe reaction of carbon tetrachloride with ethylene in the presence of acatalyst as follows. Carbon tetrachloride (CCl₄) and ethylene arereacted in the presence of iron metal, iron chlorides, and a trialkylphosphate, such as tributylphosphate (TBP), to produce1,1,1,3-tetrachloropropane in a continuous or batch process. Excesscarbon tetrachloride is fed into the reaction mixture, so that theproduct liquid contains unreacted carbon tetrachloride. The productliquid is distilled, producing an overhead mixture of carbontetrachloride and 1,1,1,3-tetrachloropropane, and a bottoms mixturecontaining catalyst components (the iron and phosphorus containingspecies), 1,1,1,3-tetrachloropropane, and high-boiling byproducts.

In general, the term “batch process” refers to a mode of carrying out achemical process in which the process begins with the reagents which arereacted under suitable reaction conditions for a suitable time andconverted to product. The process is then terminated, and the reactionmixture containing the product is collected. The reaction mixture istypically further processed in order to isolate and/or purify theproduct from unreacted starting materials. On the other hand, the term“continuous process” refers to a mode of carrying out a chemical processin which, once the process has been established, reagents are added to avessel in which reaction is occurring and products are simultaneouslyremoved. Ideally, a continuous process may be operated to convert asubstantially continuous stream of starting materials into asubstantially continuous stream of products. “Substantiallycontinuously” or “substantially continuous” when referring to additionof reagents, removal of products or other operations (such as heating,cooling, agitating, etc) performed as a part of chemical processes meanthat the operation is carried out over a period of time during thecourse of the process, in contrast to batch-wise or periodic performanceof such operations. The terms are not meant, however, to exclude thepossibility of periodic interruption in the operation.

The bottoms mixture is generally partly recycled to the1,1,1,3-tetrachloropropane reactor, and partly purged (e.g., in someinstances, the purging can control catalyst degradation and high-boilsconcentration in the system). The term “high-boils” as used hereinrefers to materials that either are not volatile, or have normal boilingpoints higher than that of a preferred product, such as1,1,1,3-tetrachloropropane. The normal boiling point of1,1,1,3-tetrachloropropane is about 155 to 160° C. The overhead mixtureof CCl₄ and 1,1,1,3-tetrachloropropane can be sent without furtherpurification to a subsequent reaction step. Alternatively, some or moste.g., 0-100%, of the carbon tetrachloride can be separated from the1,1,1,3-tetrachloropropane, and some or most of the carbon tetrachloridecan be recycled to the 1,1,1,3-tetrachloropropane reactor, while the1,1,1,3-tetrachloropropane is sent to the next reaction step. It ispreferred that the mixture going to the next reaction step shouldcontain from 3 to 30 wt % carbon tetrachloride, so that any excess overthis amount may be separated and recycled or purged.

2. Processes for Producing 1,1,1,2,3-Pentachloropropane

1,1,1,2,3-Pentachloropropane may be formed by a process wherein1,1,1,3-tetrachloropropane is reacted with chlorine in the presence offerric chloride catalyst to produce 1,1,1,2,3-pentachloropropane andhydrogen chloride.

Without wishing to be bound by theory, it is believed that the1,1,1,3-tetrachloropropane is dehydrochlorinated, in the presence offerric chloride, producing 1,1,3-trichloropropene as an intermediate insitu, which adds chlorine in a reaction also catalyzed by ferricchloride, to produce 1,1,1,2,3-pentachloropropane as shown below. Thepresent process, however, is generally carried out in one chemicaloperation, without the intermediate isolation or purification of1,1,3-trichloropropene prior to the reaction which forms1,1,1,2,3-pentachloropropane, although unreacted 1,1,3-trichloropropenemay be collected and recycled into the process. Preferably the crudeproduct from the process contains a ratio of at least 1.5:1 by weight of1,1,1,2,3-pentachloropropane to 1,1,3-trichloropropene, more preferablyat least about 2:1, 3:1, 5:1, 9:1, 10:1, 100:1, 1000:1, or 5000:1 orgreater.

Further dehydrochlorination catalyzed by ferric chloride can result information of 1,1,2,3-tetrachloropropene as a desirable byproduct formedaccording to the following scheme:

The 1,1,1,3-tetrachloropropane feedstock used as starting material forthis process can generally be obtained by any convenient method. In someembodiments, the 1,1,1,3-tetrachloropropane feedstock may contain up toabout 50 wt % carbon tetrachloride, and up to 5 wt % total ofchlorinated hydrocarbons such as perchloroethylene, chloroform,1,2-dichloroethane, chlorobutane, trichloropropene, etc. The1,1,1,3-tetrachloropropane feedstock used generally does not containmore than 1000 ppm each of water, trialkylphosphate, alcohols, or othermaterials that strongly bind with or deactivate Lewis acid catalystssuch as ferric chloride. The total amount of such deactivating compoundsis preferably less than 1000 ppm by weight. The chlorine feedstock isgenerally substantially pure and dry; it contains less than about 0.5 wt% water, and more preferably less than 0.05 wt % water. The ferricchloride catalyst is generally anhydrous, containing no more than 3 wt %water. The ferric chloride catalyst is generally handled as a solid.

The reaction is generally performed by heating a reaction mixturecontaining 1,1,1,3-tetrachloropropane, ferric chloride and chlorine toproduce 1,1,1,2,3-pentachloropropane. The reaction mixture may furthercontain carbon tetrachloride, for example in an amount up to about 50 wt% of the reaction mixture, for example from about 3 to about 30 wt %.The ferric chloride is preferably present in the mixture in a catalyticamount, preferably 25000 ppm or lower, for example about 5000 ppm, 2000ppm, or 1000 ppm or lower. The ferric chloride may be present in anamount in the range of from about 10 to about 25000 ppm, from about 20to about 5000 or about 20 to about 10000 ppm, from about 30 to about2000 ppm, from about 30 to about 1000 ppm, or from about 50 to about2000 ppm, or from about 50 to about 1000 ppm for example.

In some embodiments at least a portion of the process is performed inequipment which includes a reaction zone, a separation zone and acondensing zone.

Hydrogen chloride is a coproduct of the process. In some embodiments,the hydrogen chloride coproduct is removed from the reaction zonethrough a separation zone and a condensing zone. When the hydrogenchloride exits the reaction zone it may contain impurities, for example1,1,3-trichloropropene and/or carbon tetrachloride. In some embodimentsof the process, the separation zone may comprise an empty tube or a tubecontaining packing or other structure suitable for promotingvapor-liquid contacting, and the condensing zone may comprise a vesselsuitable for causing some of the components of the hydrogen chloridestream, such as 1,1,3-trichloropropene or carbon tetrachloride, tocondense as a liquid. In some embodiments of the process, the hydrogenchloride exiting the reaction zone contains 1,1,3-trichloropropeneand/or carbon tetrachloride and 1,1,3-trichloropropene and/or carbontetrachloride are recycled into the reaction zone via the condensingzone.

In some embodiments of the process, the reaction temperature for thereaction to form 1,1,1,2,3-pentachloropropane is in a range from about40° C. to about 120° C.

In some embodiments of the process, the reaction pressure is in a rangefrom about 1 to about 300 psig.

The 1,1,1,2,3-pentachloropropane can be produced in a semi-batch orcontinuous process.

For a semi-batch process, 1,1,1,3-tetrachloropropane liquid feedstock isgenerally placed with ferric chloride solid in a vessel equipped withmeans for agitation and temperature control. The mixture is generallyheated and agitated at a temperature between 40° C. and 120° C., whilechlorine gas is introduced below the surface of the liquid at a rate lowenough that the reaction temperature remains controllable, and highenough to consume a substantial fraction of the 1,1,3-trichloropropeneintermediate as it forms.

In a semi-batch operation, the various process conditions should beregulated so as to keep the 1,1,3-tetrachloropropene concentration inthe liquid below about 20 wt % at all times during the reaction. In acontinuous operation, the various process conditions should be regulatedto keep the steady-state 1,1,3-tetrachloropropene concentration in theliquid below about 5 wt %.

The hydrogen chloride coproduct of the process forming1,1,1,2,3-pentachloropropane is generally allowed to escape the reactor,for example, through a pressure control valve. The pressure isoptionally controlled at from 0 to 300 psig, and more preferably from 2to 100 psig. In some embodiments, the hydrogen chloride-containingstream is cooled to condense organic materials such as carbontetrachloride or 1,1,3-trichloropropene, and return these materials tothe reactor.

When the process is performed in semi-batch mode, it is not required toexactly match the rate of chlorine feed to the rate of1,1,3-trichloropropene production, but in some preferred embodiments,the rates are set to substantially match. The rate of chlorine feed maybe directly controlled. The rate of 1,1,3-trichloropropene productionmay be indirectly controlled, and may vary with time. The rate of1,1,3-trichloropropene production may be influenced by the concentrationof ferric chloride catalyst and the temperature. If too much chlorine isfed relative to the rate of 1,1,3-trichloropropene production, thenunreacted chlorine can exit the reactor with hydrogen chloridecoproduct. If too little chlorine is fed relative to the rate of1,1,3-trichloropropene production, then a relatively high concentrationof 1,1,3-trichloropropene can build up in the reactor. This material canbe consumed by continued addition of chlorine. But high concentrationsof 1,1,3-trichloropropene may be somewhat undesirable, as this conditioncan produce higher levels of high-boiling undesirable byproducts. Insemi-batch mode, the rate of chlorine feed should preferably becontrolled to limit the concentration of 1,1,3-trichloropropene in thereactor liquid to between about 0.03 and 20 wt % at any time during thereaction, and more preferably between 0.03 and 10 wt %.

Depending on the temperature and ferric chloride activity, and thechlorine feed rate, the semi-batch process can take, for example, fromabout 0.5 to about 24 hours to complete. Completion is generally markedby conversion of more than 90% of the 1,1,1,3-tetrachloropropane fed toproducts, and by conversion of more than 90% of the resulting1,1,3-trichlororopropene to products.

For a continuous process, 1,1,1,3-tetrachloropropane liquid feedstockand chlorine gas are generally fed substantially continuously to areactor equipped with means for agitation and temperature control.Hydrogen chloride coproduct is taken out continuously, optionally via apressure control valve. In some embodiments, the hydrogenchloride-containing stream is cooled so that condensed organic materialssuch as 1,1,3-trichloropropene and carbon tetrachloride may be returnedto the reactor. The liquid product can be taken out continuously, forexample via such conventional means as a level-controlled pump, etc. Insome preferred embodiments, the chlorine gas is sparged into the liquid.

Ferric chloride can be added substantially continuously or periodically.If the ferric chloride is added periodically, then a fixed amount isgenerally be added at least once per 0.5 to three turnovers of thereactor liquid, where turnover time is calculated as follows. The liquidreactor effluent flow rate is F[liters/hr], and the inventory of liquidin the reactor is V[liters]; which provide the turnover time asτ[hr]=V/F. Reactor liquid temperature is generally maintained between40° C. and 120° C. Reactor pressure is generally maintained between 0psig and 300 psig. Turnover time is generally between 0.5 hour and 24hours. Ferric chloride concentration in the reactor liquid is generallyin the range from about 30 ppm to about 1000 ppm, for example from about30 ppm and about 1000 ppm, by weight. Thechlorine/1,1,1,3-tetrachloropropane feed ratio is preferably about 0.90to 1.10 mol/mol, and more preferably between 1.01 and 1.05 mol/mol.

Without wishing to be bound by any theory, it is believed that carefulcontrol of the chlorine/1,1,1,3-tetrachloropropane feed ratio is usefulfor at least two reasons. First, if too little chlorine is fed, thenexcessive amounts of compounds containing six carbon atoms can beformed. It may be that such six-carbon compounds form by the reaction oftwo three-carbon molecules, such as two 1,1,3-trichloropropenemolecules. Second, if too much chlorine is fed, then excessive amountsof overchlorinated materials can be formed. Both of these circumstancescould result in unwarranted consumption of valuable materials andproduction of unnecessary amounts of waste.

In some embodiments, the 1,1,1,3-tetrachloropropane feedstock containsfrom about 0.0 wt % to about 50 wt % carbon tetrachloride. It ispreferable that the 1,1,1,3-tetrachloropropane feedstock should containfrom 3 to 30 wt % carbon tetrachloride.

The reactor can be operated so as to produce very low concentrations of1,1,3-trichloropropene in the effluent, for example, less than 3 wt %,or so as to produce considerable amounts, say, more than 3 wt %. If theintended application for the 1,1,3-trichloropropene is to make1,1,1,2,3-pentachloropropane, then it is preferable to operate thereactor so as to produce very low concentrations of1,1,3-trichloropropene in the liquid reactor effluent, and to returnnearly all of the 1,1,3-trichloropropene contained in the hydrogenchloride vent stream to the reactor. If there are other desirableapplications for 1,1,3-trichloropropene, then the reactor may beoperated so as to produce both 1,1,3-trichloropropene, recoverable fromthe reactor vent stream, and 1,1,1,2,3-pentachloropropane, contained inthe reactor liquid effluent stream. It is preferable in all cases tomaintain low concentrations of 1,1,3-trichloropropene in the liquidreactor effluent.

The desired product produced by the processes described above is crude1,1,1,2,3-pentachloropropane liquid. In some embodiments, the productalso contains ferric chloride catalyst, and small amounts of one or moreof unreacted 1,1,1,3-tetrachloropropane, 1,1,3-trichloropropeneintermediate, 1,1,2,3-tetrachloropropene byproduct. In some embodiments,the crude product includes a small amount of undesired byproducts suchas hexachloropropane. Optionally, the crude 1,1,1,2,3-pentachloropropaneliquid further purified. The concentration of1,1,1,2,3-pentachloropropane in the crude liquid is generally higherthan 50 wt %. In some embodiments, the crude liquid contains up to about30 wt % carbon tetrachloride. The concentration of1,1,1,3-tetrachloropropane in the crude 1,1,1,2,3-pentachloropropaneproduct is generally lower than about 5 wt %. In some embodiments of theprocess, crude 1,1,1,2,3-pentachloropropane is removed from the reactionzone. In some embodiments of the process, crude1,1,1,2,3-pentachloropropane is removed from the reaction zoneperiodically. In some embodiments of the process, crude1,1,1,2,3-pentachloropropane is removed from the reaction zonesubstantially continuously.

FIG. 1 depicts an exemplary process of making1,1,1,2,3-pentachloropropane (HCC240db). As shown in FIG. 1,1,1,1,3-tetrachloropropane, carbon tetrachloride, ferric chloride, andchlorine are fed into a reaction zone. The reaction is maintained at atemperature such that at least a portion of the reaction and productsmove into the separation and/or condensing zone. At least a portion ofthe hydrogen chloride product is removed by exiting the condensing zone.The 1,1,1,2,3-pentachloropropane product is removed from the reactionzone in a liquid effluent.

3. Processes for Producing 1,1,2,3-Tetrachloropropene

1,1,2,3-Tetrachloropropene may be formed by a process in which1,1,1,2,3-pentachloropropane is dehydrochlorinated in the presence offerric chloride catalyst to produce 1,1,2,3-tetrachloropropene productand hydrogen chloride coproduct.

The 1,1,1,2,3-pentachloropropane used for the preparation of1,1,2,3-tetrachloropropene may be prepared by one of the aforementionedprocesses for preparing 1,1,1,2,3-pentachloropropane. In someembodiments, the crude 1,1,1,2,3-pentachloropropane reactor effluentfrom a reactor in which 1,1,1,2,3-pentachloropropane is formed isdehydrochlorinated directly, without prior purification and withoutadded catalysts or reagents.

In some embodiments, the 1,1,2,3-tetrachloropropene product issubstantially free of 2,3,3,3-tetrachloropropene. The aforementionedferric chloride-catalyzed dehydrochlorination may avoid the use ofsodium hydroxide or aqueous alkali for dehydrochlorination of1,1,1,2,3-pentachloropropane.

Purified 1,1,1,2,3-pentachloropropane or crude1,1,1,2,3-pentachloropropane that contains ferric chloride catalyst isgenerally fed to a reactive distillation system. Alternatively, or inaddition, ferric chloride may be separately added to the system. Thiswould certainly be necessary if purified 1,1,1,2,3-pentachloropropane isemployed as feedstock.

Ferric chloride may be added during the course of the reaction and suchaddition can be continuous or periodic. When ferric chloride is added,the ferric chloride may be added to the process periodically. Forexample, ferric chloride may be fed into the reaction zone at least onceper 0.5 to 3 liquid turnovers, and wherein one turnover is the timecalculated as the ratio of liquid inventory in the reactor to the liquidflow rate out of the reactor. Alternatively, the ferric chloride may beadded continuously. The amount of ferric chloride maintained in thereaction zone is preferably a catalytic amount, for example about 50000ppm or lower. The ferric chloride may be present in an amount in therange of from about 10 to about 50000 ppm, from about 100 to about 25000ppm, or from about 1000 to about 20000 ppm, for example. In someembodiments, during the course of the reaction an amount in the rangefrom about 30 to about 20000 ppm by weight, for example about 1000 toabout 20000 ppm, of ferric chloride is maintained in the reaction zone.

A process for the preparation of 1,1,2,3-tetrachloropropene may usereactive distillation. In general such a process includesdehydrochlorinating 1,1,1,2,3-pentachloropropane in a reaction zone inthe presence of ferric chloride to produce 1,1,2,3-tetrachloropropeneand hydrogen chloride, wherein the 1,1,2,3-tetrachloropropene and thehydrogen chloride are removed from the reaction zone by distillationduring the course of the dehydrochlorination reaction, for example beingremoved as they form, continuously or substantially continuously.Preferably, unpurified product liquid from the1,1,1,2,3-pentachloropropane reactor, which already contains ferricchloride catalyst, is fed continuously to a reactive distillationsystem. The system can be equipped with a reaction zone, a separationzone, and a condensing zone. The feed enters the reaction zone, which isgenerally located below the separation zone. The liquid in the reactionzone is heated and agitated. Any means for providing agitation and heatcan be used. For example, the agitation can be provided via pumpedcirculation loops, or by stirring. Heat can be provided through a jacketon the vessel, or by internal heat exchangers, or by external heatexchangers. Preferably, the reactor liquid does not contain more than1000 ppm each of water, trialkylphosphate, alcohols, or other materialsthat strongly bind with or deactivate Lewis acid catalysts such asferric chloride. The total of such deactivating compounds is generallyless than 1000 ppm by weight. Optionally, means for adding more ferricchloride catalyst are included. Such addition can be continuous orperiodic.

The reactive distillation system may be operated in a continuous processwherein reagent addition and product removal are performed at the sametime.

When the process is performed as a continuous process, a reagentsolution comprising 1,1,1,2,3-pentachloropropane and ferric chloride maybe introduced periodically or substantially continuously into thereaction zone. The reagent solution may be a crude, partially purifiedor purified product from the above-described processes of preparing1,1,1,2,3-pentachloropropane. The reagent solution used for thesynthesis of 1,1,2,3-tetrachloropropene may further contain one or moreof carbon tetrachloride, 1,1,3-trichloropropene,1,1,1,3-tetrachloropropane, or hexachloropropane. The reaction zone maybe substantially free of sodium hydroxide or aqueous sodium hydroxide.

In the reactive distillation system, products may be removed from theliquid reaction mixture reaction zone as well as by distillation.

In some embodiments, the liquid reaction mixture, which comprisesunreacted 1,1,1,2,3-pentachloropropane, ferric chloride, non-volatilematerial, and high-boiling by-products, is removed from the reactionzone. The liquid reaction mixture may be removed continuously orsubstantially continuously from the reaction zone. Alternatively, theliquid reaction mixture may be removed periodically. The unreacted1,1,1,2,3-pentachloropropane contained in the liquid reaction mixtureremoved from the reaction zone may be substantially separated from othercomponents and recycled into the reaction zone.

Generally, two product streams exit the reactive distillation system.The bottom stream continuously or periodically removes high-boiling ornon-boiling materials such as unreacted 1,1,1,2,3-pentachloropropane,hexachloropropane, pentachlorohexene, hexachlorohexane, and ferricchloride. The overhead stream continuously removes1,1,2,3-tetrachloropropene product, hydrogen chloride, and, in someembodiments, unreacted 1,1,1,2,3-pentachloropropane,1,1,1,3-tetrachloropropane, and 1,1,3-trichloropropene. The overheadstream generally removes carbon tetrachloride, if such is present in thefeed.

The reactive distillation is generally performed using reactivedistillation equipment which includes a reaction zone, a separationzone, and a condensing zone. The separation zone is generally positionedvertically above the reaction zone. In a simple embodiment, theseparation could comprise a tube. In some embodiments, however, theseparation zone may contain a surface, for example packing material orother structures, suitable for promoting efficient contact of vapor andliquid streams. The separation zone therefore promotes separation ofmore volatile and less volatile components of the reaction mixture.

The liquid in the reaction zone contains the ferric chloride catalyst,most of the unreacted pentachloropropane, and some of the reactionproducts. The dehydrochlorination reaction generally occurs in thereaction zone. The separation zone is generally operated at an overheadpressure of about 100 to about 600 torr, to provide a bottomstemperature in the reaction zone ranging from about 120° C. to about180° C. The 1,1,2,3-tetrachloropropene product continuously exits thereaction zone through the separation zone, together with hydrogenchloride. In some embodiments, the separation zone keeps most of theunreacted 1,1,1,2,3-pentachloropropane in the reaction zone, and allowsmost of the 1,1,2,3-tetrachloropropene product to escape the reactionzone.

In the condensing zone, the vapor stream is generally cooled, thuscausing 1,1,2,3-tetrachloropropene, unreacted1,1,1,2,3-pentachloropropane, and components such as carbontetrachloride, 1,1,1,3-tetrachloropropane, and 1,1,3-trichloropropane tocondense. The uncondensed hydrogen chloride can be further purified orsent elsewhere for disposal or employment. In some embodiments, aportion of the condensate may be returned to the separation zone asreflux liquid, and a portion may be removed as product. For example,about 10% of the condensed 1,1,2,3-tetrachloropropene may be removed asproduct. The product may optionally be sent to a product purificationsystem for further purification.

In some embodiments, a product purification system produces purified1,1,2,3-tetrachloropropene product suitable for its intendedapplication, and separates other components of the reactive distillationcolumn overhead stream. For example, carbon tetrachloride,1,1,3-trichloropropene, and/or 1,1,1,3-tetrachloropropane can berecovered in suitably pure form, and either recycled into any of theaforementioned chemical processes employing the particular compound, orelse sent to other employment.

By operating the reactive distillation system at sub-atmosphericpressure, and thereby reduced temperature, tar and polymer formation canbe reduced. A continuous or periodic purge can be taken from thereaction zone to maintain the ferric chloride concentration in a rangefrom about 1000 ppm to about 20000 ppm by weight. This purge can alsoremove the catalytically inactive iron-containing tars and polymers, aswell as catalyst poisons, if any are present. The purge thus can beoperated to maintain catalytic activity and to remove high-boiling andnon-boiling contaminants from the system.

Crude 1,1,2,3-tetrachloropropene product is generally continuouslyremoved from the separation zone overhead. The continuous removal canreduce the quantity of 1,1,2,3-tetrachloropropene in contact with theferric chloride catalyst in the reaction zone. While not being bound bytheory, it is believed this reduces the likelihood of the olefinreducing the catalytically active ferric chloride to inactive ferrouschloride, which can help preserve the catalyst life. The crude1,1,2,3-tetrachloropropene overhead product can be further distilled ina conventional manner to remove any undesired lower and higher boilingcompounds.

FIG. 2 depicts an exemplary process for producing1,1,2,3-tetrachloropropene. 1,1,1,2,3-Pentachloropropane and ferricchloride are fed into a reaction zone. The reaction zone is maintainedat a temperature and pressure such that at least a portion of thereaction products move into the separation and/or condensing zones. Atleast a portion of the hydrogen chloride product is removed by exitingthe condensing zone. At least a portion of crude1,1,2,3-tetrachloropropene product is condensed in the condensing zoneand subsequently removed from the process.

FIG. 3 depicts a synergistic process for producing1,1,2,3-tetrachloropropene. 1,1,1,3-Tetrachloropropane, ferric chloride,and chlorine, and optionally carbon tetrachloride (not shown), are fedinto a reaction zone shown in the upper portion of FIG. 3. The reactionis maintained at a temperature such that at least a portion of thereaction products move into the separation and/or condensing zones. Atleast a portion of the hydrogen chloride product is removed by exitingthe condensing zone. The 1,1,1,2,3-pentachloropropane product is removedfrom the reaction zone in a liquid effluent and subsequently introducedinto a second reaction zone shown in the lower portion of FIG. 3. Thesecond reaction zone is maintained at a temperature such that at least aportion of the reaction products move into the separation and/orcondensing zone. At least a portion of the hydrogen chloride product isremoved by exiting the condensing zone. At least a portion of crude1,1,2,3-tetrachloropropene product is condensed in the condensing zoneand subsequently removed from the process.

FIG. 4 depicts an exemplary synergistic process for producing1,1,2,3-tetrachloropropene. Ethylene, iron metal, carbon tetrachloride,and trialkylphosphate are introduced into a first reaction zone, shownnear the top of FIG. 4. The liquid reactor effluent passes into a firstseparation zone, which separates the first reactor effluent into anoverhead and a bottoms stream. The bottoms stream, which containscatalyst components, is partly returned to the first reaction zone andpartly purged. The overhead stream, which contains1,1,1,3-tetrachloropropane product and unreacted carbon tetrachloride,passes to a second reaction zone, shown near the center of FIG. 4.Chlorine and ferric chloride catalyst are also introduced into thesecond reaction zone, where 1,1,1,2,3-pentachloropropane and hydrogenchloride are produced. At least some of the hydrogen chloride product isremoved as a gas via the overhead separation and condensing zones. Atleast some of the 1,1,3-trichloropropene byproduct and the carbontetrachloride solvent, and other volatile organic materials, arecondensed and returned to the reaction zone via the separation andcondensing zones. The liquid effluent from the second reaction zonecontains, at least, 1,1,1,2,3-pentachloropropane product and ferricchloride catalyst. This material is transferred to a third reactionzone, shown near the bottom of FIG. 4. In the third reaction zone,1,1,1,2,3-pentachloropropane is catalytically dehydrochlorinated toproduce 1,1,2,3-tetrachloropropene and hydrogen chloride. At least someof the 1,1,2,3-tetrachloropropene and hydrogen chloride products passthrough the separation zone into the condensing zone, wherein some ofthe 1,1,2,3-tetrachloropropene is condensed, and thereby separated fromhydrogen chloride gas. This partly purified hydrogen chloride gas isremoved from the condensing zone. The condensed1,1,2,3-tetrachloropropene product is partly returned to the separationzone as reflux liquid, and partly removed as crude1,1,2,3-tetrachloropropene product liquid. The latter may be furtherpurified by any known means. A liquid purge stream is taken from thethird reaction zone. This stream contains ferric chloride catalyst,unreacted 1,1,1,2,3-pentachloropropane, and high-boiling or non-volatilebyproducts.

EXAMPLES Examples 1-4 Formation of 1,1,2,3-Tetrachloropropene

The equipment used in examples 1-4 was a 20-tray, 25 mm i.d.vacuum-jacketed Pyrex laboratory distillation column equipped with a1-liter bottoms flask and means for operation at sub-atmosphericpressure. A pump continuously fed liquid material directly into thebottoms flask. A swinging-bucket type reflux head allowed controlledwithdrawal of overhead product. A separate pump removed liquid from thebottoms flask periodically.

Table 1 shows the run conditions for examples 1-4. Overhead formationrate of the 1,1,2,3-tetrachloropropene product is shown in FIG. 1.

TABLE 1 Conditions for Examples 1-4 Example number 1 2 3 4 overheadpressure torr 280 495 480 350 bottoms ° C. 159-160 173-177 169-179154-157 temperature bottoms residence hr 4.5 7 8 8 time liquid feedsource Synthetic Synthetic tetrachloropropane tetrachloropropanechlorination chlorination liquid feed composition 1,1,1,2,3- wt % 45.090.8 61.0 80.0 pentachloropropane misc. chlorocarbons wt % 55.0 9.2 39.020.0 FeCl₃ ppmw 0 0 0 280 solid FeCl₃ added g 0.27 0.96 0 0 reactorFeCl₃ ppmw 1000 2030 148 2100 concentration ppmw = parts per million byweight

Example 1

The bottoms flask of the distillation column was charged with a mixtureof about 90 percent 1,1,1,2,3-pentachloropropane, with about 10 percentother miscellaneous chlorocarbons. About 0.27 grams of solid anhydrousferric chloride was added to the liquid, with stirring, giving a bottomsferric chloride concentration of 1000 ppmw. The column pressure wasadjusted to 280 torr, and sufficient heat was applied to the bottomsflask to reflux liquid in the column. A synthetic feed comprised of 45percent 1,1,1,2,3-pentachloropropane and 55 percent other miscellaneouschlorocarbons was fed continuously to the bottoms flask to give a liquidresidence time in the bottoms of approximately 4.5 hours. The syntheticfeed contained no ferric chloride. Liquid draw from the reflux head wasstarted simultaneously with the feed at a rate sufficient to maintainthe liquid level in the bottoms flask. The formation rate of1,1,2,3-tetrachloropropene, as measured by the overhead liquidcomposition and collection rate, was less than 0.02 mole/hr, indicatingvery little dehydrochlorination of the pentachloropropane occurred. Thebottoms temperature over the course of the test ranged from 159-160° C.

Example 2

The bottoms flask of a distillation column was charged with a mixture ofabout 96 percent 1,1,1,2,3-pentachloropropane, with about four percentother miscellaneous chlorocarbons. About 0.96 grams of solid anhydrousferric chloride was added to the liquid, with stirring, to give abottoms ferric chloride concentration of 2030 ppmw. The column pressurewas adjusted to 495 torr, and sufficient heat was applied to the bottomsflask to reflux liquid in the column. A synthetic feed comprised of 90.8percent 1,1,1,2,3-pentachloropropane and 9.2 percent other miscellaneouschlorocarbons was fed continuously to the bottoms flask so as to give aliquid residence time in the bottoms of approximately 7 hours. The feedcontained no ferric chloride. Liquid draw from the reflux head wasstarted simultaneously with the feed at a rate sufficient to maintainthe liquid level in the bottoms flask. The formation rate of1,1,2,3-tetrachloropropene, as measured by the overhead liquidcomposition and collection rate, peaked at 0.49 mole/hr, at 5.7 hoursrun time, as shown in FIG. 5. The formation rate then began to steadilyfall to below 0.19 mole/hr at 16 hours. The bottoms temperature over thecourse of the test steadily increased from 173-177° C.

Example 3

A feed mixture containing 1,1,1,2,3-pentachloropropane was prepared byliquid-phase chlorination of 1,1,1,3-tetrachloropropane in the presenceof dissolved ferric chloride. The unpurified chlorination product,containing approximately 80 percent 1,1,1,2,3-pentachloropropane, 20percent other miscellaneous chlorocarbons, and 150 ppmw ferric chloride,was charged to the bottoms flask of the distillation column. Noadditional solid ferric chloride was added to the liquid. The columnpressure was adjusted to 480 torr, and sufficient heat was applied tothe bottoms flask to reflux liquid in the column. Then, a synthetic feedcomprised of 61 percent 1,1,1,2,3-pentachloropropane and 39 percentother miscellaneous chlorocarbons was fed continuously to the bottomsflask so as to give a liquid residence time in the bottoms ofapproximately 8 hours. The feed contained no ferric chloride. Liquiddraw from the reflux head was started simultaneously with the feed at arate sufficient to maintain the liquid level in the bottoms flask. Theformation rate of 1,1,2,3-tetrachloropropene, as measured by theoverhead liquid composition and collection rate, peaked at 0.24 mole/hrat 8.2 hours run time, as shown in FIG. 5. The formation rate thenrapidly fell to below 0.03 mole/hr at 13 hours, indicating thedehydrochlorination reaction had nearly stopped. The bottoms temperatureover the course of the test steadily increased from 169-179° C.

Example 4

A feed mixture containing primarily 1,1,1,2,3-pentachloropropane wasprepared by liquid-phase chlorination of 1,1,1,3-tetrachloropropane inthe presence of dissolved ferric chloride. The crude chlorinationproduct, containing approximately percent 1,1,1,2,3-pentachloropropane,20 percent other miscellaneous chlorocarbons, and 280 ppmw ferricchloride, was charged to the bottoms flask of the distillation column.No additional solid ferric chloride was added to the liquid. The columnpressure was adjusted to 350 torr, and sufficient heat was applied tothe bottoms flask to reflux liquid in the column. The crudetrichloropropene chlorination product containing 80 percent1,1,1,2,3-pentachloropropane, 20 percent other miscellaneouschlorocarbons, and 280 ppmw ferric chloride was fed continuously to thebottoms flask so as to give a liquid residence time of approximately 8hours. Liquid draw from the reflux head was started simultaneously withthe feed at a rate sufficient to maintain the liquid level in thebottoms flask. Liquid was withdrawn from the bottoms flask every 2-3hours of operation. The volume of the liquid withdrawn was about sevenpercent of the volume of material fed over that same time period. Theformation rate of 1,1,2,3-tetrachloropropene, as measured by theoverhead liquid composition and collection rate, rose to over 0.40mole/hr by five hours run time, as shown in FIG. 5. The formation rateremained between 0.4 and 0.55 moles/hr for over 70 hours of operation,with no sign of decreasing. The bottoms temperature over the course ofthe test remained between 154-157° C. Ferric chloride concentration inthe bottoms rose to approximately 2100 ppmw by 40 hours of operation andremained constant.

Examples 5-6 Semibatch 1,1,1,2,3-Pentachloropropane Reactions Example 5No Carbon Tetrachloride

A mixture of 655 ppm ferric chloride in 99+% pure1,1,1,3-tetrachloropropane feedstock was heated and stirred in a 1-literflask at 54-60 C for 6.22 hours, while 0.68 to 0.82 moles of chlorineper hour per kg of liquid feed was fed. Hydrogen chloride exited thereactor continuously, via a water cooled condenser, and then through apressure control valve. Reactor pressure was kept at about 5-7 psig.Samples of liquid were taken from the reactor periodically, with thefollowing results:

TABLE 2 Results of Example 5 time hr 0.00 1.30 2.35 3.50 4.50 6.22sample no. 53202501 53302701 53302703 53302801 53302803 53302805 weight,total, G 817 820 835 815 845 909 postulated chlorine feed mol/hr/kg 0.680.75 0.82 0.79 0.74 temperature avg. C 52.9 54.3 54.7 57.7 55.9concentrations FeCl₃ wt % 0.065 0.065 0.064 0.066 0.063 0.059 propene,1,1,3- wt % 0.00 0.14 2.57 22.14 14.80 1.09 trichloro- propane, 1,1,1,3-wt % 99.93 86.96 73.93 21.63 14.32 8.31 tetrachloro- propene, 1,1,2,3-wt % 0.00 0.05 0.21 0.46 0.62 0.93 tetrachloro- propane, 1,1,1,2,3- wt %0.00 2.70 17.34 33.19 44.13 65.55 pentachloro- total GC wt % 100.0091.56 95.81 88.37 82.88 86.72 Components useful product mol/kg 5.49 4.925.05 4.27 3.88 3.61 yield, on 1,1,1,3- tetrachloropropane propane,1,1,1,2,3- % 2.3 14.9 27.9 38.4 61.4 pentachloro- useful product % 89.994.0 77.5 73.0 73.2

In this and the following tables, “useful product” refers to the sum of1,1,1,2,3-pentachloropropane, 1,1,2,3-tetrachloropropene, and1,1,3-trichloropropene. The yields are calculated on1,1,1,3-tetrachloropropane fed. “GC” refers to Gas Chromatographicanalyses of the indicated liquid samples.

An important observation on this table is that the “useful product”declined after the sample at 2.35 hour from 94% yield on1,1,1,3-tetrachloropropane fed to 73%. Likewise, the total GC componentsdeclined from 96% at 2.35 hours to 87% at the end of 6.2 hours. The GCshowed increasing amounts of components that, judging by the retentiontimes, boil considerably higher than 1,1,1,2,3-pentachloropropane. Forexample, the last sample, no. 53302805, contained twenty-threecomponents with retention times longer than1,1,1,2,3-pentachloropropane, totaling 8.7 area % on the sample. Thus,high boilers were being produced at undesirably high rates.

Example 6 With Carbon Tetrachloride in Feed

A mixture of 51.6 wt % carbon tetrachloride and 48.3 wt %1,1,1,3-tetrachloropropane was stirred and heated with 608 ppm ferricchloride. This experiment ran for 4.75 hours, feeding 0.59 to 0.73 molesof chlorine per hour per kg of liquid feed, keeping the temperaturearound 53-55 C.

TABLE 3 Results of Example 6 Time hr 0.00 1.25 2.00 2.95 3.90 4.75sample no. 53303101 53304401 53304403 53304405 53304501 53304504 weight,total, postulated g 893 903 914 938 965 965 chlorine feed mol/hr/kg 0.620.73 0.71 0.69 0.59 temperature avg. C. 53.3 54.3 54.6 54.7 52.9Pressure psig 5.7 5.5 5.1 5.0 5.7 Concentrations FeCl₃ wt % 0.061 0.0600.059 0.058 0.056 0.056 carbon tetrachloride wt % 51.63 49.82 48.8347.01 44.77 43.69 propene, 1,1,3- wt % 0.09 5.38 4.93 0.04 0.03trichloro- propane, 1,1,1,3- wt % 48.31 41.41 22.27 6.97 2.44 1.22tetrachloro- propene, 1,1,2,3- wt % 0.10 0.35 0.66 0.65 0.07tetrachloro- propane, 1,1,1,2,3- wt % 7.51 23.35 37.81 47.35 47.00pentachloro- total GC components wt % 100.00 99.41 101.03 100.17 98.1195.20 useful product mol/kg 2.66 2.63 2.69 2.51 2.36 2.25 yield, on1,1,1,3- tetrachloropropane fed propane, 1,1,1,2,3- % 13.2 41.6 69.189.1 88.4 pentachloro- useful product % 100.4 103.9 99.1 96.2 91.4

In this case, total “useful product” declined from 99% yield on1,1,1,3-tetrachloropropane fed at 2.95 hours, to 91% yield at 4.75hours. The last sample, 53304504, contained ten components that elutedafter 1,1,1,2,3-pentachloropropane on the GC, totaling 2.7 area %. Thepeak yield of 1,1,1,2,3-pentachloropropane was 89%, at 3.9 hours.Comparison of Example 6 with Example 5 shows an improvement in resultscaused by the presence of carbon tetrachloride in the feeds.

Examples 7-10 Continuous 1,1,1,2,3-Pentachloropropane Reactions Example7

The equipment shown in FIG. 6 was employed.

For this experiment (trial number 53315304) the feed mixture wasproduced in a pilot plant unit. The pilot plant unit reacted carbontetrachloride and ethylene in a 10-gallon stirred vessel, in thepresence of ferric chloride, iron metal, and tributylphosphate. Thereactor effluent was distilled to separate 1,1,1,3-tetrachloropropaneand lower boiling materials (the overhead fraction) from higher boilingmaterials, including iron and phosphorus compounds. The overheadfraction (sample number 53313710) contained 13.6 wt % carbontetrachloride, 84.8 wt % 1,1,1,3-tetrachloropropane, 0.23 wt %chloroform, 0.08 wt % 1-chlorobutane, 0.17 wt % perchloroethylene, and1.1 wt % other volatile materials. It was a clear colorless liquid.

Some of this overhead fraction was placed in D1, shown in FIG. 6. Thismaterial was fed into the reactor, via the pump P1, at 200 grams perhour. Ferric chloride solid was periodically weighed into D2, which wasmade of ¼″ OD polytetrafluoroethylene tubing. About 0.3 gram ferricchloride was added to the reactor every two hours of operation. Theaverage ferric chloride concentration in the reactor liquid was 740 ppmby weight. Chlorine was fed via a 0.125″ OD polytetrafluoroethylenetubing, which extended below the surface of the liquid. The chlorine to1,1,1,3-tetrachloropropane feed ratio was 1.00 mol/mol. The reactorliquid was stirred at about 110 rpm. Reactor liquid temperature wasmaintained at about 77 C, and pressure was kept at 10 psig. Reactorliquid volume was about 1.05 liters, and the estimated liquid effluentflow rate was 0.155 liters per hour, so that the estimated turnover timewas 6.8 hours. Chlorine and hydrogen chloride flow rates in the ventstream were measured via timed samples caught in potassium iodidesolution. At the end of 15.0 hours operation (about 2.0 liquidturnovers), a sample of the liquid reactor effluent was analyzed by gaschromatography.

Chlorine conversion was 99%; 1,1,1,3-tetrachloropropane conversion was99%. The yields of 1,1,3-trichloropropene, 1,1,1,2,3-pentachloropropane,and 1,1,2,3-tetrachloropropene on 1,1,1,3-tetrachloropropane fed were2.0, 85, and 5.8 percent, respectively. The total yield of fourprominent high-boiling byproducts was 3.3 wt % in the reactor effluent.These byproducts are believed to be hexachloropropane, twopentachlorohexene isomers, and hexachlorohexadiene.

Example 8

The feedstock (sample 53311408) for this example (trial 53313101) wasproduced by the same pilot plant unit as before, in the same manner. Itcontained 15.69 wt % carbon tetrachloride, 82.76 wt %1,1,1,3-tetrachloropropane, 0.18 wt % chloroform, 0.03 wt %1-chlorobutane, 0.31 wt % perchloroethylene, and 1.0 wt % other volatilematerials. The experiment was performed like Example 7, except for thefollowing changes. Reactor temperature was kept at 82 C; liquid turnovertime was 7.3 hours; ferric chloride average concentration was 550 ppm;total run time was 2.1 turnovers.

Chlorine conversion was 99%; 1,1,1,3-tetrachloropropane conversion was99%. The yields of 1,1,3-trichloropropene, 1,1,1,2,3-pentachloropropane,and 1,1,2,3-tetrachloropropene on 1,1,1,3-tetrachloropropane fed were3.4, 82.9, and 8.1 percent, respectively. The yield of the same fourundesired prominent high-boiling byproducts was 4.2 wt % in the reactoreffluent.

Example 9

The starting material for this example (trial 53315701) was produced bythe same pilot plant unit as before, in the same way. However, thecarbon tetrachloride was then separated from the1,1,1,3-tetrachloropropane by distillation, producing sample 53315501.The latter material contained 0.06 wt % carbon tetrachloride, 0.21 wt %1,1,3-trichloropropene, 0.041 wt % perchloroethylene, 99.60 wt %1,1,1,3-tetrachloropropane, and 0.09 wt % other volatile components.This material was placed in D1 and fed to the reactor. The experimentwas performed like Example 8, except for the difference in thefeedstock. Reactor temperature was kept at 82 C; liquid turnover timewas 7.3 hours; ferric chloride average concentration was 510 ppm; totalrun time was 2.1 turnovers.

Chlorine conversion was 97%; 1,1,1,3-tetrachloropropane conversion was99%. The yields of 1,1,3-trichloropropene, 1,1,1,2,3-pentachloropropane,and 1,1,2,3-tetrachloropropene on 1,1,1,3-tetrachloropropane fed were3.7, 76.7, and 7.6 percent, respectively. The yield of the usual fourundesired prominent high-boiling byproducts was 6.3 wt % in the reactoreffluent. Comparison of this experiment with Example 8 shows asignificant advantage for the feedstock containing 15.7 wt % carbontetrachloride.

Example 10

The liquid feedstock (sample 53315312) for this example (trial 53317907)was produced by the same pilot plant unit as in Example 7. It contained22.46 wt % carbon tetrachloride, 76.09 wt % 1,1,1,3-tetrachloropropane,0.23 wt % chloroform, 0.09 wt % 1-chlorobutane, 0.13 wt %perchloroethylene, and 1.0 wt % other volatile materials. The experimentwas conducted at higher temperature, with less ferric chloride catalyst,relative to Example 7. Reactor temperature was kept at 92 C; liquidturnover time was 7.2 hours; ferric chloride average concentration was180 ppm; total run time was 2.0 turnovers. Reactor pressure was 9-10psig, as usual.

Chlorine conversion was 98%; 1,1,1,3-tetrachloropropane conversion was97%. The yields of 1,1,3-trichloropropene, 1,1,1,2,3-pentachloropropane,and 1,1,2,3-tetrachloropropene on 1,1,1,3-tetrachloropropane fed were2.7, 85, and 5.7 percent, respectively. The yield of the usual fourundesired prominent high-boiling byproducts was 2.2 wt % in the reactoreffluent.

All references cited herein are hereby incorporated by reference intheir entireties. A number of embodiments of the invention have beendescribed. Nevertheless, it will be understood that variousmodifications may be made without departing from the spirit and scope ofthe invention. Accordingly, other embodiments are within the scope ofthe following claims.

1. A process for producing 1,1,2,3-tetrachloropropene, the processcomprising: i. preparing 1,1,1,2,3-pentachloropropane by combining1,1,1,3-tetrachloropropane and chlorine within a reaction vessel in thepresence of carbon tetrachloride and a catalyst that catalyzes thedehydrochlorination of 1,1,1,3-tetrachloropropane to one or moretrichloropropenes and promotes the addition of chlorine to the one ormore trichloropropenes; ii. removing the 1,1,1,2,3-pentachloropropanefrom the reaction vessel; iii. optionally combining the1,1,1,2,3-pentachloropropane with ferric chloride to form a mixture of1,1,1,2,3-pentachloropropane and ferric chloride; and iv. heating themixture of 1,1,1,2,3-pentachloropropane and ferric chloride to produce1,1,2,3-tetrachloropropene.
 2. The process of claim 1, where said stepof heating takes place within a reaction zone of a reactive distillationsystem.
 3. The process of claim 2, where the reactive distillationsystem includes a separation zone above the reaction zone.
 4. Theprocess of claim 3, where the separation zone is maintained at about 100to about 600 torr.
 5. The process of claim 4, where said mixture isagitated during said step of heating.
 6. The process of claim 1, wheresaid mixture does not include more than 1000 ppm of water,trialkylphosphate, and alcohol.
 7. The process of claim 1, where said1,1,1,2,3-pentachloropropane is removed from the reaction vessel withina crude product stream, and where the crude product stream is combinedwith ferric chloride.
 8. The process of claim 1, where said1,1,1,2,3-pentachloropropane is removed from the reaction vessel withina crude product stream, and where the 1,1,1,2,3-pentachloropropane isisolated from the crude product stream prior to said step of combiningthe 1,1,1,2,3-pentachloropropane with ferric chloride.
 9. The process ofclaim 1, where said step of heating takes place at about 120° C. toabout 180° C.
 10. The process of claim 1, where the process includes thestep of combining the 1,1,1,2,3-pentachloropropane with ferric chloride.11. A process for producing 1,1,2,3-tetrachloropropene, the processcomprising: i. preparing 1,1,1,2,3-pentachloropropane by combining1,1,1,3-tetrachloropropane and chlorine within a reaction vessel in thepresence of carbon tetrachloride and a catalyst that catalyzes thedehydrochlorination of 1,1,1,3-tetrachloropropane to one or moretrichloropropenes and promotes the addition of chlorine to the one ormore trichloropropenes; ii. removing the 1,1,1,2,3-pentachloropropanefrom the reaction vessel; iii. combining the1,1,1,2,3-pentachloropropane with a catalyst that catalyzes thedehydrochlorination of the 1,1,1,2,3-pentachloropropane to form amixture of the 1,1,1,2,3-pentachloropropane and the catalyst, where saidmixture includes less than 1000 ppm of water, trialkylphosphate,alcohol, or other materials that may deactivate the catalyst; and iv.heating the mixture of 1,1,1,2,3-pentachloropropane and the catalyst toproduce 1,1,2,3-tetrachloropropene.
 12. The process of claim 11, wheresaid step of heating takes place within a reaction zone of a reactivedistillation system.
 13. The process of claim 12, where the reactivedistillation system includes a separation zone above the reaction zone.14. The process of claim 13, where the separation zone is maintained atabout 100 to about 600 torr.
 15. The process of claim 14, where saidmixture is agitated during said step of heating.
 16. The process ofclaim 15, where said agitation is provided by a pumped circulation loop.17. The process of claim 11, where said 1,1,1,2,3-pentachloropropane isremoved from the reaction vessel within a crude product stream, andwhere the catalyst is ferric chloride.
 18. The process of claim 11,where said 1,1,1,2,3-pentachloropropane is removed from the reactionvessel within a crude product stream, and where the1,1,1,2,3-pentachloropropane is isolated from the crude product streamprior to said step of combining the 1,1,1,2,3-pentachloropropane withthe catalyst.
 19. The process of claim 11, where said step of heatingtakes place at about 120° C. to about 180° C.